What is Photosynthetic Photon Flux Density (PPFD) and Micromoles (μmols)
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Source From 420expertguide:
There are two other phrases related to photosynthetically active radiation (PAR) that you need to understand when growing cannabis. Those phrases are Photosynthetic Photon Flux Density (PPFD) and Micromoles (μmols). This is the light intensity requirements for cannabis plants.
1 Mole = 1,000,000 MicroMoles (μmols)
If we Calculate per Day, We usually say Mole of Light.
If we Calculate per Second, We usually say MicroMoles (μmols) of Light.
PPFD is the amount of light photons that hit a surface (your plant canopy) in one second. It’s measured in units called micromoles (μmols). Simply speaking – it’s the strength of the light that reaches your plants.
The light loses strength as it travels from source to endpoint (from grow light to plant). You’ll notice on most grow light intensity charts, the PPFD numbers decrease with increased distance from the light.
That’s why paying attention to your grow light hanging height is so important when growing cannabis.
Most Manufacturer or Products Data Sheet would list PAR Value or PPFD Map or PPFD Chart,
Take our Products B900 Pro as an example!
The Par Value is :
12”/30cm : 1258 μmol/s : Means light hanging height is 12 feet ，and All Cannabis on Coverage 4X6 feet can get at least 1258 μmols per second. Equal to 4.259 Moles per Hour, If Lighting is 12 Hours per day, Cannabis in Coverage 4X6 feet can 54 Moles Per day; If Lighting is 18 Hours per day,Every Cannabis in Coverage 4X6 feet can 76.67 Moles Per day
24”/60cm : 586 μmol/s : Means light hanging height is 24 feet ，and All Cannabis on Coverage 4X6 feet can get at least 586 μmols per second. Equal to 2.11 Moles per Hour, If Lighting is 12 Hours per day, Cannabis in Coverage 4X6 feet can 25.32 Moles Per day; If Lighting is 18 Hours per day,Every Cannabis in Coverage 4X6 feet can 37.98 Moles Per day
36”/90cm : 449 μmol/s : Means light hanging height is 36 feet ，and All Cannabis on Coverage 4X6 feet can get at least 449 μmols per second. Equal to 1.62 Moles per Hour, If Lighting is 12 Hours per day, Cannabis in Coverage 4X6 feet can 19.4 Moles Per day; If Lighting is 18 Hours per day, Every Cannabis in Coverage 4X6 feet can 29.16 Moles Per day
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Control and Customization
Remember that you’ll be changing the lighting cycles depending on the growth stage to ensure that your plants thrive:
Seedling stage: 16 hours on/8 hours off
Veg stage: 18 hours on/6 hours off
Flowering stage: 12 hours on/12 hours off
About PPFD , See https://cannabis.ledlight.cc/question/what-is-ppfd-in-cannabis-plant-growth?ref=μmols
Photosynthetic Photon Flux Density or PPFD refers to the amount of light that gets to your plants. In other words, various things can prevent light from reaching a plant’s surface, so a light’s rating of what it is generating at the source isn’t always telling the full story. More Information Please Visit: https://cannabis.ledlight.cc/the_best_led_grow_lights_for_cannabis_417.html?ref=answer